A-horizon


Also found in: Thesaurus.
Related to A-horizon: soil profile
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.A-horizon - the top layer of a soil profileA-horizon - the top layer of a soil profile; usually contains humus
humus - partially decomposed organic matter; the organic component of soil
References in periodicals archive ?
For example, in Tasman Bay (northern South Island) fieldwork, 5-12 cm thick alluvial gravel sediments are associated with A-Horizon Maori soils of the lower Waimea River catchment in and around Appleby, and at site N26/80 near Motueka River mouth (Figure 2; Barber 2010; Challis 1976).
This is illustrated by Factor 1 in the A-horizon and Factor 2 in the B- and C-horizons loading heavily on Cd, Pb, and Zn, Factor 2 in the A-horizon and Factor 3 in the Band C-horizons loading heavily on Co and Fe, and Factor 3 in the A-horizon and Factor 1 in the B- and C-horizons loading heavily on Cu, Mo, and Ni (Table 4).
Cumulative runoff correlated with the coarse sand content in the A-horizon and organic carbon content in the top 30 mm of the soil (Table 6).
Comparisons of A-horizon thickness, organic carbon content, and bulk density indicate that the A horizon depletion has greatly diminished from its earlier pace.
By this time, the whole surface was covered with the forest floor beneath which the A-horizon had formed even in the absence of the ground vegetation (Table 1).
tillage operations and water erosion, the whole A-horizon was displaced or washed out from the upper parts (summit, shoulder, backslope) of the hillslope and deposited in the lower parts (footslope, toeslope)--burying the original soil surface (Figure 5).
The average bulk density of all mixtures for both the Coonalpyn and Bordertown sites increased with increasing amounts of clay-rich subsoil aggregates mixed with the pure A-horizon sand (Table 2).
As a result of humus accumulation, the depth of the A-horizon (10YR3/1) is 8 cm; it is commonly rooted by fine and medium roots, and its boundary is gradually clear and smooth.
Interflow through the A-horizon will accumulate and persist for longer within the lower parts of the landscape, leading to paler A-horizon colours.
2]O), and P retention, and A-horizon total C, total N, exchangeable Ca, and A-horizon thickness.